My problem is that, my fan would not work or spin at all. I found this out when i was fiddling around Ubuntu and started up Mozilla. While i was surfing around, the laptop switched off by itself. Then, i touched the vent and it was uber hot. I booted into Windows and the fan works just fine as normal.

Hi!
I'm the owner of a brazilian rebranded Benq S57. We have the same problem around, but as far as I could check, it's a problem in the bios. I'm not sure BenQ has a new bios for that (in Brazil nobody tried the BenQ Bios, since the first guy ever to try it used the wrong program and lost his motherboard... ok, that was probably the program's fault, not the bios, but can you convince someone else to test in such a situation? ;) ).
Anyway, I could solve my problems appending the option during boot time (after you edit your grub configuration, for some reason I'm not aware, you must first **turn off** your system and then start it again will probably go fine. A simple restart *does not* work, ok?):
acpi.power_nocheck=1
This can be done by
sudo gedit /etc/default/grub
And then edit the line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
into:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi.power_nocheck=1"
After that, just update your grub:
sudo update-grub2
(or is it just update-grub?) and turn off your system. The next power on, your cooler will be working fine, I guess.
Sincerely,
Ricardo